common/env_eeprom.c

   1 /*
   2  * (C) Copyright 2000-2010
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   6  * Andreas Heppel <aheppel@sysgo.de>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <command.h>
  13 #include <environment.h>
  14 #include <linux/stddef.h>
  15 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  16 #include <i2c.h>
  17 #endif
  18 #include <search.h>
  19 #include <errno.h>
  20 #include <linux/compiler.h>     /* for BUG_ON */
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 env_t *env_ptr;
  25
  26 char *env_name_spec = "EEPROM";
  27 int env_eeprom_bus = -1;
  28
  29 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
  30                            uchar *buffer, unsigned cnt)
  31 {
  32         int rcode;
  33 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  34         int old_bus = i2c_get_bus_num();
  35
  36         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  37                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  38 #endif
  39
  40         rcode = eeprom_read(dev_addr, offset, buffer, cnt);
  41
  42 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  43         if (old_bus != env_eeprom_bus)
  44                 i2c_set_bus_num(old_bus);
  45 #endif
  46
  47         return rcode;
  48 }
  49
  50 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
  51                             uchar *buffer, unsigned cnt)
  52 {
  53         int rcode;
  54 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  55         int old_bus = i2c_get_bus_num();
  56
  57         if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
  58                 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
  59 #endif
  60
  61         rcode = eeprom_write(dev_addr, offset, buffer, cnt);
  62
  63 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
  64         i2c_set_bus_num(old_bus);
  65 #endif
  66         return rcode;
  67 }
  68
  69 uchar env_get_char_spec(int index)
  70 {
  71         uchar c;
  72         unsigned int off = CONFIG_ENV_OFFSET;
  73
  74 #ifdef CONFIG_ENV_OFFSET_REDUND
  75         if (gd->env_valid == 2)
  76                 off = CONFIG_ENV_OFFSET_REDUND;
  77 #endif
  78         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  79                         off + index + offsetof(env_t, data), &c, 1);
  80
  81         return c;
  82 }
  83
  84 void env_relocate_spec(void)
  85 {
  86         char buf[CONFIG_ENV_SIZE];
  87         unsigned int off = CONFIG_ENV_OFFSET;
  88
  89 #ifdef CONFIG_ENV_OFFSET_REDUND
  90         if (gd->env_valid == 2)
  91                 off = CONFIG_ENV_OFFSET_REDUND;
  92 #endif
  93         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
  94                         off, (uchar *)buf, CONFIG_ENV_SIZE);
  95
  96         env_import(buf, 1);
  97 }
  98
  99 int saveenv(void)
 100 {
 101         env_t   env_new;
 102         ssize_t len;
 103         char    *res;
 104         int     rc;
 105         unsigned int off        = CONFIG_ENV_OFFSET;
 106 #ifdef CONFIG_ENV_OFFSET_REDUND
 107         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 108         char flag_obsolete      = OBSOLETE_FLAG;
 109 #endif
 110
 111         BUG_ON(env_ptr != NULL);
 112
 113         res = (char *)&env_new.data;
 114         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 115         if (len < 0) {
 116                 error("Cannot export environment: errno = %d\n", errno);
 117                 return 1;
 118         }
 119         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
 120
 121 #ifdef CONFIG_ENV_OFFSET_REDUND
 122         if (gd->env_valid == 1) {
 123                 off     = CONFIG_ENV_OFFSET_REDUND;
 124                 off_red = CONFIG_ENV_OFFSET;
 125         }
 126
 127         env_new.flags = ACTIVE_FLAG;
 128 #endif
 129
 130         rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 131                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 132
 133 #ifdef CONFIG_ENV_OFFSET_REDUND
 134         if (rc == 0) {
 135                 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
 136                                  off_red + offsetof(env_t, flags),
 137                                  (uchar *)&flag_obsolete, 1);
 138
 139                 if (gd->env_valid == 1)
 140                         gd->env_valid = 2;
 141                 else
 142                         gd->env_valid = 1;
 143         }
 144 #endif
 145         return rc;
 146 }
 147
 148 /*
 149  * Initialize Environment use
 150  *
 151  * We are still running from ROM, so data use is limited.
 152  * Use a (moderately small) buffer on the stack
 153  */
 154 #ifdef CONFIG_ENV_OFFSET_REDUND
 155 int env_init(void)
 156 {
 157         ulong len, crc[2], crc_tmp;
 158         unsigned int off, off_env[2];
 159         uchar buf[64], flags[2];
 160         int i, crc_ok[2] = {0, 0};
 161
 162         eeprom_init();  /* prepare for EEPROM read/write */
 163
 164         off_env[0] = CONFIG_ENV_OFFSET;
 165         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
 166
 167         for (i = 0; i < 2; i++) {
 168                 /* read CRC */
 169                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 170                                 off_env[i] + offsetof(env_t, crc),
 171                                 (uchar *)&crc[i], sizeof(ulong));
 172                 /* read FLAGS */
 173                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 174                                 off_env[i] + offsetof(env_t, flags),
 175                                 (uchar *)&flags[i], sizeof(uchar));
 176
 177                 crc_tmp = 0;
 178                 len = ENV_SIZE;
 179                 off = off_env[i] + offsetof(env_t, data);
 180                 while (len > 0) {
 181                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 182
 183                         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
 184                                         buf, n);
 185
 186                         crc_tmp = crc32(crc_tmp, buf, n);
 187                         len -= n;
 188                         off += n;
 189                 }
 190
 191                 if (crc_tmp == crc[i])
 192                         crc_ok[i] = 1;
 193         }
 194
 195         if (!crc_ok[0] && !crc_ok[1]) {
 196                 gd->env_addr    = 0;
 197                 gd->env_valid   = 0;
 198
 199                 return 0;
 200         } else if (crc_ok[0] && !crc_ok[1]) {
 201                 gd->env_valid = 1;
 202         } else if (!crc_ok[0] && crc_ok[1]) {
 203                 gd->env_valid = 2;
 204         } else {
 205                 /* both ok - check serial */
 206                 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
 207                         gd->env_valid = 1;
 208                 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
 209                         gd->env_valid = 2;
 210                 else if (flags[0] == 0xFF && flags[1] == 0)
 211                         gd->env_valid = 2;
 212                 else if (flags[1] == 0xFF && flags[0] == 0)
 213                         gd->env_valid = 1;
 214                 else /* flags are equal - almost impossible */
 215                         gd->env_valid = 1;
 216         }
 217
 218         if (gd->env_valid == 2)
 219                 gd->env_addr = off_env[1] + offsetof(env_t, data);
 220         else if (gd->env_valid == 1)
 221                 gd->env_addr = off_env[0] + offsetof(env_t, data);
 222
 223         return 0;
 224 }
 225 #else
 226 int env_init(void)
 227 {
 228         ulong crc, len, new;
 229         unsigned off;
 230         uchar buf[64];
 231
 232         eeprom_init();  /* prepare for EEPROM read/write */
 233
 234         /* read old CRC */
 235         eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 236                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 237                         (uchar *)&crc, sizeof(ulong));
 238
 239         new = 0;
 240         len = ENV_SIZE;
 241         off = offsetof(env_t, data);
 242
 243         while (len > 0) {
 244                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 245
 246                 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
 247                                 CONFIG_ENV_OFFSET + off, buf, n);
 248                 new = crc32(new, buf, n);
 249                 len -= n;
 250                 off += n;
 251         }
 252
 253         if (crc == new) {
 254                 gd->env_addr    = offsetof(env_t, data);
 255                 gd->env_valid   = 1;
 256         } else {
 257                 gd->env_addr    = 0;
 258                 gd->env_valid   = 0;
 259         }
 260
 261         return 0;
 262 }
 263 #endif